//-----------------------------------------------------------------------------
// MurmurHash3 was written by Austin Appleby, and is placed in the public
// domain. The author hereby disclaims copyright to this source code.

// Note - The x86 and x64 versions do _not_ produce the same results, as the
// algorithms are optimized for their respective platforms. You can still
// compile and run any of them on any platform, but your performance with the
// non-native version will be less than optimal.

#include "MurmurHash3.h"

//-----------------------------------------------------------------------------
// Platform-specific functions and macros

// Microsoft Visual Studio

#if defined(_MSC_VER)

#define FORCE_INLINE	__forceinline

#include <stdlib.h>
#include <stdint.h>

#define ROTL32(x,y)	_rotl(x,y)
#define ROTL64(x,y)	_rotl64(x,y)

#define BIG_CONSTANT(x) (x)

// Other compilers

#else									  // defined(_MSC_VER)

#define	FORCE_INLINE inline __attribute__((always_inline))

static inline uint32_t rotl32(uint32_t x, int8_t r)
{
	return (x << r) | (x >> (32 - r));
}

static inline uint64_t rotl64(uint64_t x, int8_t r)
{
	return (x << r) | (x >> (64 - r));
}

#define	ROTL32(x,y)	rotl32(x,y)
#define ROTL64(x,y)	rotl64(x,y)

#define BIG_CONSTANT(x) (x##LLU)

#endif								  // !defined(_MSC_VER)

//-----------------------------------------------------------------------------
// Block read - if your platform needs to do endian-swapping or can only
// handle aligned reads, do the conversion here

FORCE_INLINE uint32_t getblock32(const uint32_t * p, int i)
{
	return p[i];
}

FORCE_INLINE uint64_t getblock64(const uint64_t * p, int i)
{
	return p[i];
}

//-----------------------------------------------------------------------------
// Finalization mix - force all bits of a hash block to avalanche

FORCE_INLINE uint32_t fmix32(uint32_t h)
{
	h ^= h >> 16;
	h *= 0x85ebca6b;
	h ^= h >> 13;
	h *= 0xc2b2ae35;
	h ^= h >> 16;

	return h;
}

//----------

FORCE_INLINE uint64_t fmix64(uint64_t k)
{
	k ^= k >> 33;
	k *= BIG_CONSTANT(0xff51afd7ed558ccd);
	k ^= k >> 33;
	k *= BIG_CONSTANT(0xc4ceb9fe1a85ec53);
	k ^= k >> 33;

	return k;
}

//-----------------------------------------------------------------------------

void MurmurHash3_x86_32(const void *key, int len, uint32_t seed, void *out)
{
	const uint8_t *data = (const uint8_t *)key;
	int i, nblocks = len / 4;

	uint32_t h1 = seed;

	uint32_t c1 = 0xcc9e2d51;
	uint32_t c2 = 0x1b873593;

	//----------
	// body

	const uint32_t *blocks = (const uint32_t *)(data + nblocks * 4);

	for (i = -nblocks; i; i++) {
		uint32_t k1 = getblock32(blocks, i);

		k1 *= c1;
		k1 = ROTL32(k1, 15);
		k1 *= c2;

		h1 ^= k1;
		h1 = ROTL32(h1, 13);
		h1 = h1 * 5 + 0xe6546b64;
	}

	//----------
	// tail

	const uint8_t *tail = (const uint8_t *)(data + nblocks * 4);

	uint32_t k1 = 0;

	switch (len & 3) {
	case 3:
		k1 ^= tail[2] << 16;
	case 2:
		k1 ^= tail[1] << 8;
	case 1:
		k1 ^= tail[0];
		k1 *= c1;
		k1 = ROTL32(k1, 15);
		k1 *= c2;
		h1 ^= k1;
	};

	//----------
	// finalization

	h1 ^= len;

	h1 = fmix32(h1);

	*(uint32_t *) out = h1;
}

//-----------------------------------------------------------------------------

void MurmurHash3_x86_128(const void *key, const int len, uint32_t seed, void *out)
{
	const uint8_t *data = (const uint8_t *)key;
	int i, nblocks = len / 16;

	uint32_t h1 = seed;
	uint32_t h2 = seed;
	uint32_t h3 = seed;
	uint32_t h4 = seed;

	uint32_t c1 = 0x239b961b;
	uint32_t c2 = 0xab0e9789;
	uint32_t c3 = 0x38b34ae5;
	uint32_t c4 = 0xa1e38b93;

	//----------
	// body

	const uint32_t *blocks = (const uint32_t *)(data + nblocks * 16);

	for (i = -nblocks; i; i++) {
		uint32_t k1 = getblock32(blocks, i * 4 + 0);
		uint32_t k2 = getblock32(blocks, i * 4 + 1);
		uint32_t k3 = getblock32(blocks, i * 4 + 2);
		uint32_t k4 = getblock32(blocks, i * 4 + 3);

		k1 *= c1;
		k1 = ROTL32(k1, 15);
		k1 *= c2;
		h1 ^= k1;

		h1 = ROTL32(h1, 19);
		h1 += h2;
		h1 = h1 * 5 + 0x561ccd1b;

		k2 *= c2;
		k2 = ROTL32(k2, 16);
		k2 *= c3;
		h2 ^= k2;

		h2 = ROTL32(h2, 17);
		h2 += h3;
		h2 = h2 * 5 + 0x0bcaa747;

		k3 *= c3;
		k3 = ROTL32(k3, 17);
		k3 *= c4;
		h3 ^= k3;

		h3 = ROTL32(h3, 15);
		h3 += h4;
		h3 = h3 * 5 + 0x96cd1c35;

		k4 *= c4;
		k4 = ROTL32(k4, 18);
		k4 *= c1;
		h4 ^= k4;

		h4 = ROTL32(h4, 13);
		h4 += h1;
		h4 = h4 * 5 + 0x32ac3b17;
	}

	//----------
	// tail

	const uint8_t *tail = (const uint8_t *)(data + nblocks * 16);

	uint32_t k1 = 0;
	uint32_t k2 = 0;
	uint32_t k3 = 0;
	uint32_t k4 = 0;

	switch (len & 15) {
	case 15:
		k4 ^= tail[14] << 16;
	case 14:
		k4 ^= tail[13] << 8;
	case 13:
		k4 ^= tail[12] << 0;
		k4 *= c4;
		k4 = ROTL32(k4, 18);
		k4 *= c1;
		h4 ^= k4;

	case 12:
		k3 ^= tail[11] << 24;
	case 11:
		k3 ^= tail[10] << 16;
	case 10:
		k3 ^= tail[9] << 8;
	case 9:
		k3 ^= tail[8] << 0;
		k3 *= c3;
		k3 = ROTL32(k3, 17);
		k3 *= c4;
		h3 ^= k3;

	case 8:
		k2 ^= tail[7] << 24;
	case 7:
		k2 ^= tail[6] << 16;
	case 6:
		k2 ^= tail[5] << 8;
	case 5:
		k2 ^= tail[4] << 0;
		k2 *= c2;
		k2 = ROTL32(k2, 16);
		k2 *= c3;
		h2 ^= k2;

	case 4:
		k1 ^= tail[3] << 24;
	case 3:
		k1 ^= tail[2] << 16;
	case 2:
		k1 ^= tail[1] << 8;
	case 1:
		k1 ^= tail[0] << 0;
		k1 *= c1;
		k1 = ROTL32(k1, 15);
		k1 *= c2;
		h1 ^= k1;
	};

	//----------
	// finalization

	h1 ^= len;
	h2 ^= len;
	h3 ^= len;
	h4 ^= len;

	h1 += h2;
	h1 += h3;
	h1 += h4;
	h2 += h1;
	h3 += h1;
	h4 += h1;

	h1 = fmix32(h1);
	h2 = fmix32(h2);
	h3 = fmix32(h3);
	h4 = fmix32(h4);

	h1 += h2;
	h1 += h3;
	h1 += h4;
	h2 += h1;
	h3 += h1;
	h4 += h1;

	((uint32_t *) out)[0] = h1;
	((uint32_t *) out)[1] = h2;
	((uint32_t *) out)[2] = h3;
	((uint32_t *) out)[3] = h4;
}

//-----------------------------------------------------------------------------

void MurmurHash3_x64_128(const void *key, const int len, const uint32_t seed, void *out)
{
	const uint8_t *data = (const uint8_t *)key;
	int i, nblocks = len / 16;

	uint64_t h1 = seed;
	uint64_t h2 = seed;

	uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
	uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);

	//----------
	// body

	const uint64_t *blocks = (const uint64_t *)(data);

	for (i = 0; i < nblocks; i++) {
		uint64_t k1 = getblock64(blocks, i * 2 + 0);
		uint64_t k2 = getblock64(blocks, i * 2 + 1);

		k1 *= c1;
		k1 = ROTL64(k1, 31);
		k1 *= c2;
		h1 ^= k1;

		h1 = ROTL64(h1, 27);
		h1 += h2;
		h1 = h1 * 5 + 0x52dce729;

		k2 *= c2;
		k2 = ROTL64(k2, 33);
		k2 *= c1;
		h2 ^= k2;

		h2 = ROTL64(h2, 31);
		h2 += h1;
		h2 = h2 * 5 + 0x38495ab5;
	}

	//----------
	// tail

	const uint8_t *tail = (const uint8_t *)(data + nblocks * 16);

	uint64_t k1 = 0;
	uint64_t k2 = 0;

	switch (len & 15) {
	case 15:
		k2 ^= ((uint64_t) (tail[14])) << 48;
	case 14:
		k2 ^= ((uint64_t) (tail[13])) << 40;
	case 13:
		k2 ^= ((uint64_t) (tail[12])) << 32;
	case 12:
		k2 ^= ((uint64_t) (tail[11])) << 24;
	case 11:
		k2 ^= ((uint64_t) (tail[10])) << 16;
	case 10:
		k2 ^= ((uint64_t) (tail[9])) << 8;
	case 9:
		k2 ^= ((uint64_t) (tail[8])) << 0;
		k2 *= c2;
		k2 = ROTL64(k2, 33);
		k2 *= c1;
		h2 ^= k2;

	case 8:
		k1 ^= ((uint64_t) (tail[7])) << 56;
	case 7:
		k1 ^= ((uint64_t) (tail[6])) << 48;
	case 6:
		k1 ^= ((uint64_t) (tail[5])) << 40;
	case 5:
		k1 ^= ((uint64_t) (tail[4])) << 32;
	case 4:
		k1 ^= ((uint64_t) (tail[3])) << 24;
	case 3:
		k1 ^= ((uint64_t) (tail[2])) << 16;
	case 2:
		k1 ^= ((uint64_t) (tail[1])) << 8;
	case 1:
		k1 ^= ((uint64_t) (tail[0])) << 0;
		k1 *= c1;
		k1 = ROTL64(k1, 31);
		k1 *= c2;
		h1 ^= k1;
	};

	//----------
	// finalization

	h1 ^= len;
	h2 ^= len;

	h1 += h2;
	h2 += h1;

	h1 = fmix64(h1);
	h2 = fmix64(h2);

	h1 += h2;
	h2 += h1;

	((uint64_t *) out)[0] = h1;
	((uint64_t *) out)[1] = h2;
}

//-----------------------------------------------------------------------------

uint64_t MurmurHash64A(const void *key, int len, unsigned int seed)
{

	const uint64_t m = BIG_CONSTANT(0xc6a4a7935bd1e995);
	const int r = 47;

	uint64_t h = seed ^ (len * m);

	const uint64_t *data = (const uint64_t *)key;
	const uint64_t *end = data + (len / 8);

	while (data != end) {
		uint64_t k = *data++;

		k *= m;
		k ^= k >> r;
		k *= m;

		h ^= k;
		h *= m;
	}

	const unsigned char *data2 = (const unsigned char *)data;

	switch (len & 7) {
	case 7:
		h ^= (uint64_t) (data2[6]) << 48;
	case 6:
		h ^= (uint64_t) (data2[5]) << 40;
	case 5:
		h ^= (uint64_t) (data2[4]) << 32;
	case 4:
		h ^= (uint64_t) (data2[3]) << 24;
	case 3:
		h ^= (uint64_t) (data2[2]) << 16;
	case 2:
		h ^= (uint64_t) (data2[1]) << 8;
	case 1:
		h ^= (uint64_t) (data2[0]);
		h *= m;
	};

	h ^= h >> r;
	h *= m;
	h ^= h >> r;

	return h;
}

uint64_t MurmurHash64B(const void *key, int len, unsigned int seed)
{

	const unsigned int m = 0x5bd1e995;
	const int r = 24;

	unsigned int h1 = seed ^ len;
	unsigned int h2 = 0;

	const unsigned int *data = (const unsigned int *)key;

	while (len >= 8) {

		unsigned int k1 = *data++;
		k1 *= m;
		k1 ^= k1 >> r;
		k1 *= m;
		h1 *= m;
		h1 ^= k1;
		len -= 4;

		unsigned int k2 = *data++;
		k2 *= m;
		k2 ^= k2 >> r;
		k2 *= m;
		h2 *= m;
		h2 ^= k2;
		len -= 4;
	}

	if (len >= 4) {

		unsigned int k1 = *data++;
		k1 *= m;
		k1 ^= k1 >> r;
		k1 *= m;
		h1 *= m;
		h1 ^= k1;
		len -= 4;
	}

	switch (len) {

	case 3:
		h2 ^= ((unsigned char *)data)[2] << 16;
	case 2:
		h2 ^= ((unsigned char *)data)[1] << 8;
	case 1:
		h2 ^= ((unsigned char *)data)[0];
		h2 *= m;
	};

	h1 ^= h2 >> 18;
	h1 *= m;
	h2 ^= h1 >> 22;
	h2 *= m;
	h1 ^= h2 >> 17;
	h1 *= m;
	h2 ^= h1 >> 19;
	h2 *= m;

	uint64_t h = h1;

	h = (h << 32) | h2;

	return h;
}
